<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>

        console.log(100)

        setTimeout( () => {
            console.log(200)
        } ) // 宏任务

        Promise.resolve().then( () => {
            console.log(300)
        } ) // 微任务

        console.log(400)
        
        // 100
        // 400
        // 300
        // 200
        // 微任务执行时机比宏任务早

    </script>
</body>
</html>